| Nowadays, the manufacturing of moulds and dies is more and more exigent and competitive, presenting greater requirements of dimensional precision and surface roughness as well as a decrease in costs and manufacturing time. With the introduction of new technologies such as high speed machining, it is possible to achieve these requirements in an efficient way. For its so many advantages and potential, the high-speed milling has been widely used in model-manufacturing industry. Present the high-speed milling is paid considerable attention in the whole word, with it has promoting function in improvement of machining efficiency and melioration of product quality.On the other hand, the high-speed milling principle and craft can not keep up with the development of equipment. Such technology's complexity that accurately control, along with their continuous evolution, make it difficult for the final user and the manufacturer. Lots of user select the machining parameters using his/her own experience or from the handbooks base on the part material, the machine tool. They plan the tool path of high-speed milling used the conventional methods. That will result in low quality of part as well as useless of tool machine function. So it is an important research topic to present an effective approach for selecting machining parameters and planning tool path.This research carries on"Automatic programming system in high-speed milling of mould based on intelligent process decision". Some questions about machining parameter in high-speed milling of mold and tool path planning is carried on developing deeply on the basis of reading and analysis the domestic and foreign literature material in the paper.T10 steel is a kind of carbon tool steel, which is application very extensive in the industry and the main material of the mould .In this research field, we will find the disciplinarian of T10 steel's surface roughness relation to cutting conditions such as: rotate speed of spindle, speed of feed, radial depth of cut and cutting depth. We used SANDVIC's cemented carbides tool (2 teeth), doing 31 times second-order rolling regressive tests with D165 HSM centre of FIDIA. After data processing, getting second-order model is:From regression significance test, we can see this second-order model is significance very well, and it can be used for estimate, control or selecting machining parameters.We may obtain the following conclusion from the regression model and Fig.1: In the condition of high-speed milling, T10 steel's surface quality was enhanced with the rotate speed of spindle faster, and it would reduce if feed speed faster. When increases the radial feed of cut, the surface quality reduces first, then elevates. The influence of cutting depth is similar with radial feed of cut. Moreover, the influence of rotate speed of main axis and feed speed is more than the others.Then the estimated value of Ra is 0.2233μm. The coefficient the modelλ1 is negative, that means along ? 1axis departing from the point x 0, response will reduced. The coefficientλ2λ3λ4are positive number, that means response will increase when depart from x 0.The point x 0is a saddle point.In the study of tool path planning, analysis the advantages and disadvantages of the existing tool path generation algorithm (line parameters, offsetting intercept surface, etc.) and conventional cutting mode(line, circumcision and spiral cutting). Planning tool path from the generation method, cutting direction, tool path strategy, cuts-over and cuts-off, connecting at corner, based on the characteristics of high-speed spindle and high-speed feed. Then take a proposal of high-speed milling tool path planning method. High-speed milling tool path generation should be diverse. It should be based on part shape features select the appropriate method or combination of several methods. High-speed milling tool path is required simply, straight, smooth, less turn points, that means need perfect cutting direction. For smooth surface, find the longest average length path direction, when the surface uneven, determine the direction according to curvature of surface. If the curvature is big, consider the maximum radius of curvature as the optimal cutting direction, but when curvature is small, the influence of curvature radius is weakened, so still use the principle of longest average length.Ensure high-speed and precise cutting largely depends on the cutting strategy. Helix and cycloid machining is more suitable for high-speed milling. Considered the cutting force and surface quality, high-speed milling require more in the strategy of cut-over. It must be used the manner arc or several step to cut in, prohibiting cut-over direct, and avoiding changes in direction suddenly. In the present, oblique and helix manner can be used in our experience. We deal with cusp corner used the arc to optimizing the cusp, that is inserted arc in the corner.In machining, the purpose of rough machining is removing excess material rapidly, and left suitable remainder. The requirements of efficiency should be higher than the quality requirements. Moreover selecting a suitable tool is an effective way to improve the efficiency. In the same of scallop height allowable, tool path space will increase with increasing tool's radius. Thereby, processing time will reduce, and improve machining efficiency and quality because of cutting speed is faster. Therefore, it mist be choose tool's radius as large as possible. However, the tool's radius can not be large unlimited. It is restricted by the curvature of surface. If the tool's radius is too large, there may be interference phenomenon. So we must decide how to select the tool's radius in the case of not to interfere.In this research field, consider the tool's radius from the interference, and use a method by comparison Z coordinate between verge points of tool and points on the surface. Do it like this, be given an initial radius according curvature, checking every cutter points whether the interference. If intervene, decreases the tool's radius until no interference, else increase the tool's radius until one cut point intervene at least. That will determine appropriate tool's radius and ensure the tool path no interference.
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